There are many situations in which it is desirable to delay an analog electrical signal for a prespecified period of time. For example, delaying analog signals is common in processing audio signals, such as music. Conventional techniques of delaying analog signals, however, have a number of drawbacks.
Some conventional analog delay lines involve large-lumped components, such as large capacitors, resistors, and inductors, that are difficult to manufacture on a monolithic semiconductor substrate. Moreover, some conventional analog delay lines may not be able to accurately achieve small delay periods, e.g. around 1 ns. A related difficulty with conventional analog delay lines is in obtaining fine resolution within the delay periods, for example, about 200 ps.